Free tool · KNX

KNX TP topology validator

KNX TP1 sets three ceilings: 64 devices per segment, 4 segments (256 devices) per line, 15 lines per area, 15 areas per backbone. This validator confirms whether your topology is compliant or whether you need to split into segments with repeaters.

Free · no sign-upLast updated: 2026-05-20
Max 15 (AA = 0-15)
Max 15 per area (LL = 1-15)
Max 256 per line (4 segments × 64)
1 to 4; each extra segment = 1 repeater
✅ Topology compliant
Total devices
480
Total lines
8
Minimum segments per line
1

How to use

1. Enter areas (AA addressing), lines per area (LL), devices per line (DDD). 2. If a line exceeds 64 devices, increase the segment count (one repeater per extra segment). 3. The tool flags every violation in red and borderline configs in amber. 4. Cable spec: 1000 m per segment max, 350 m max between two devices, 1 SELV 30 V DC PSU per segment minimum.

Go deeper

Rules derived from the KNX Specification (3/3/2 and 3/5/1) and EN ISO/IEC 14543-3. Independent CertifBus tool, not affiliated with KNX Association.

Last updated: 2026-05-20

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